Bridge-flooring



(No Model.)

J. R. WORCESTER.

BRIDGE FLOORING.

Patentd Aug. 9, 1892.

UNITED STATES PATENT OFFICE.

JOSEPH R. WORCESTER, OF WALTHAM, ASSIGNOR OF ONE-HALF TO DAVID H.ANDREWS, OF BOSTON, MASSACHUSETTS.

BRIDGE-FLOORING.

SPECIFICATION forming part of Letters Patent No. 480,483, dated August9, 1892.

Application filed October 26, 1891.

To all whom it may concern:

Be it known that I, JOSEPH R. WoRoEsTnR, civil engineer, a citizen ofthe United States, residing at Waltham, in the county of Middlesex andState of Massachusetts, have invented certain new and usefulImprovements in Bridge-Flooring, of which the following is aspecification.

My invention relates to bridges, and moreparticularly to bridge-floors,and has for its object to provide a floor for a railroad or highwaybridge which shall be capable of sustaining a heavy load and at the sametime be of simpler and cheaper construction than others which have goneinto use, while admitting of more accurate computation of strength. 7

To this end I construct my floor of a foundation of iron put together ina peculiar way, which is more fully described hereinafter, thepeculiarities of construction and their attendant advantages beingpointed out in the specification hereunto annexed, while the elements ofnovelty are more particularly set forth in the claims.

Heretofore bridges have been floored by heavy planking laid overfloor-beams of any pattern; but with the increased speed and weight ofrailroad-trains this has become insufficient. Where the rails are soclosely attached to the bridge structure it has been found desirable toemploy a higher class of labor to repair the track than was otherwisenecessary. This has increased the outlay for maintenance of way, andhassometimes caused delay in repairs. The same reasons for a change ofpractice exist, though necessarily to a less degree, in ordinaryhighway-bridges. For the reasons indicated those railroads carryingheavy trafiic have endeavored to substitute a floor on bridges whichwould not only carry the usual live load, but would be of such strengthas to admit of a solid concrete bed topped by the usual depth ofballast, in which the ties are embedded. Upon these ties the rails arelaid. It will be seen that the roadway upon bridges is similar to otherparts of the line, and the ordinary section-hands have no difficulty inpreserving its grade and alignment. The additional strength needed has,however, been attained in some cases by having the flooring of un SerialNo. 409,851. (No model.)

adopted of flooring which has been previously used has a section showinga top horizontal line of about five inches, a similar bottom line, andan inclined line connecting the two. The inclined lines of adjacentsections lap and are joined by rivets. The main objection to this is thefact that there is an uncertainty involved in calculating the strainsproduced in this section by a concentrated load, for unless theconcentration falls over the center of a section transverse strains areproduced, which must necessarily be resisted by the transverse stiffnessof the web, which is comparatively small, and, further, in order to makethis form of section special rolls are necessary, which involve aconsiderable expense and limit the use of the form to special sizes.Another form has been a square plate having the center dished to theform of a spherical segment; but this cannot be used in many places, asit is only suitable for very short spans.

My invention obviates the defects named in previous structures, and isfully illustrated in the accompanying drawings, hereby referred to andmade a part of this specification, showing the form in which I prefer toembody my invention, in which- Figure 1 is an isometric projection; Fig.2, a cross-section on the line 2 2 of Fig. 3, looking toward the beam B;and Fig. 3 a plan of my improved floor.

A A, &c., are pieces of fiat plate-iron of a width suited to the depthof floor desired, this depth being determined by the span of the floorand the intended load. The pieces A A are connected at their edges byangle-irons O O, &c., riveted to the plain web in the usual way, so thata cross-section shows a series of triangles with one side missing, eachconnected to its neighbor at the apices of the missing side. The flooris thus composed of a series of alternate triangular prisms having anopen side. These angle-irons are shown on the inside of the angle formedby two adjacent websAA; but it is manifest that they may be on theoutside thereof Without affecting the identity of my invention. Theflooring is shown connected to an ordinary builtup I-beam B by means ofordinary brackets formed of triangular angle-iron, as shown at D, Figs.1 and 2. The flooring thus arranged has a wide range of adjustment, andmay be proportioned with great accuracy to the load to be carried. Itmay be used to span the distance between trusses, thus obviating thenecessity for cross floor-beams and stringers and saving much innecessary depth of floor. If the space between the trusses is wide, the

angles may be sharpened, and as the web is thus more nearly vertical itis greatly increased in strength. In case the span is so great that itwould require a large amount of material to so construct the floor thetrusses may be connected by floor-beams, between which my flooring maybe built in the manner set out.

In addition to the advantages already described, my flooring may beriveted by an ordinary riveting-machine, while the old forms alreadydescribed require a machine of special construction havingpeculiarlyformed jaws, involving extra expense.

Having thus described my invention, what I claim, and wish to protect byLetters Patent of the United States, is-

1. A bridge-flooring composed of a metallic web and having across-section composed of a series of triangles with one side misslng,each triangle connected to its neighbor at the apices of the missingside, substantially as described.

2. A bridge-floorin g composed of a metallic web so arranged as to forma series of alternate triangular prisms having an open side,substantially as described.

3. Abridge-fiooring composed of plain strips of plate metal, as AA,connected at their edges by angles, as O C, so as to form alternatetriangular prisms having an open side, substantially as described.

In witness whereof I' have hereunto set my hand in the presence of twowitnesses.

JOSEPH R. WORCESTER.

Witnesses:

Gno. H. WILLIAMS, J r., ERNEST T. PEVERLY.

